/* CSS Variables */
:root {
    --primary: #0A0E27;       /* Very dark navy */
    --secondary: #1A1D29;     /* Dark slate */
    --accent: #00D4FF;        /* Bright cyan */
    --accent-secondary: #FF6B6B; /* Coral red */
    --light: #FFFFFF;         /* Pure white */
    --gray-50: #F8FAFC;       /* Light gray */
    --gray-100: #F1F5F9;      /* Lighter gray */
    --gray-200: #E2E8F0;      /* Medium light gray */
    --gray-600: #475569;      /* Medium gray */
    --gray-900: #0F172A;      /* Very dark gray */
    --text: #1E293B;          /* Dark blue-gray text */
    --text-light: #64748B;    /* Light gray text */
    --text-muted: #94A3B8;    /* Muted text */
    --card-bg: #151825;       /* Card background */
    --dark: #0F172A;          /* Very dark */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

/* Emoji fallback support to prevent diamond display */
@font-face {
    font-family: 'emoji';
    src: local('Apple Color Emoji'), local('Segoe UI Emoji'), local('Segoe UI Symbol'), local('Noto Color Emoji');
    unicode-range: U+1F600-1F64F, U+1F300-1F5FF, U+1F680-1F6FF, U+1F1E0-1F1FF, U+2600-26FF, U+2700-27BF;
}

/* Apply emoji font fallback to elements that might contain emojis */
h1, h2, h3, .icon, .contact-icon, .challenge-icon, .result-icon, .use-case-icon, .process-arrow {
    font-family: 'emoji', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background-color: var(--primary);
    color: var(--light);
    line-height: 1.7;
    overflow-x: hidden;
    font-weight: 400;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--gray-100);
}

::-webkit-scrollbar-thumb {
    background: var(--accent);
}

img {
    max-width: 100%;
    height: auto;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    padding: 0 1.5rem;
    margin: 0 auto;
}

/* Animation classes for scroll animations */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

.animate-slide-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.animate-slide-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.animate-slide-right {
    opacity: 0;
    transform: translateX(50px);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.animate-slide-right.visible {
    opacity: 1;
    transform: translateX(0);
}

.animate-scale {
    opacity: 0;
    transform: scale(0.9);
    transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.animate-scale.visible {
    opacity: 1;
    transform: scale(1);
}

/* Header Styles */
header {
    background-color: var(--primary);
    color: white;
    padding: 2rem 0;
    margin-bottom: 0;
    position: relative;
    overflow: hidden;
    min-height: 60vh;
    display: flex;
    align-items: center;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(45deg, transparent 30%, rgba(0, 212, 255, 0.1) 50%, transparent 70%),
        radial-gradient(circle at 20% 80%, rgba(255, 107, 107, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(0, 212, 255, 0.1) 0%, transparent 50%);
    animation: backgroundShift 20s ease-in-out infinite;
}

header::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, 
        transparent 0%, 
        transparent 70%, 
        rgba(10, 14, 39, 0.8) 90%, 
        var(--primary) 100%);
    pointer-events: none;
    z-index: 5;
}

@keyframes backgroundShift {
    0%, 100% { transform: translateX(0) translateY(0); }
    25% { transform: translateX(-10px) translateY(-5px); }
    50% { transform: translateX(10px) translateY(5px); }
    75% { transform: translateX(-5px) translateY(10px); }
}

.logo-container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    padding-bottom: 1.5rem;
    position: relative;
    z-index: 10;
}

.logo {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -1px;
    color: white;
    text-decoration: none;
    position: relative;
    transition: all 0.3s ease;
}

.logo::after {
    content: "";
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-secondary) 100%);
    transition: width 0.3s ease;
}

.logo span {
    color: var(--accent);
}

.logo:visited {
    color: white;
}

.logo:hover, .logo:focus {
    color: var(--accent);
    transform: translateY(-2px);
}

.logo:hover::after {
    width: 80px;
}

.header-nav .nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.header-nav .nav-links li {
    position: relative;
}

.header-nav .nav-links a {
    color: white;
    text-decoration: none;
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    white-space: nowrap;
}

.header-nav .nav-links a:hover, 
.header-nav .nav-links a:focus {
    color: var(--primary);
    background-color: var(--accent);
    border-color: var(--accent);
    transform: translateY(-2px);
}

.hero {
    text-align: center;
    padding: 4rem 0;
    position: relative;
    z-index: 10;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    font-weight: 900;
    line-height: 1.1;
    letter-spacing: -2px;
}

.hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

/* Section Styles */
section {
    margin-bottom: 6rem;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--light);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -1px;
    position: relative;
}

h2::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-secondary) 100%);
}

/* Grid and Card Styles */
.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.card {
    background: linear-gradient(135deg, var(--card-bg) 0%, rgba(26, 29, 41, 0.8) 100%);
    padding: 2rem;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border: 1px solid rgba(0, 212, 255, 0.1);
    border-radius: 5px;
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-secondary) 100%);
    transform: scaleX(0);
    transition: transform 0.4s ease;
    transform-origin: left;
}

.card:hover, .card:focus {
    transform: translateY(-5px);
    border-color: rgba(0, 212, 255, 0.3);
}

.card:hover::before {
    transform: scaleX(1);
}

.card h3 {
    color: var(--light);
    margin-bottom: 1rem;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    line-height: 1.4;
    font-weight: 700;
}

.icon {
    min-width: 2.5rem;
    height: 2.5rem;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.7) 0%, rgba(255, 107, 107, 0.7) 100%);
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 1rem;
    color: white;
    font-size: 1.25rem;
    transition: transform 0.3s ease;
}

.card:hover .icon {
    transform: scale(1.1);
}

.card p {
    color: var(--light);
    opacity: 0.9;
    font-size: 1rem;
    line-height: 1.7;
}

/* Button Styles */
.btn {
    display: inline-block;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.8) 0%, rgba(255, 107, 107, 0.8) 100%);
    color: white;
    padding: 1rem 2rem;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    border-radius: 5px;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border: 2px solid transparent;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover, .btn:focus {
    transform: translateY(-3px);
    border-color: rgba(0, 212, 255, 0.6);
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.8) 0%, rgba(0, 212, 255, 0.8) 100%);
}

/* Footer Styles */
footer {
    background-color: var(--secondary);
    color: white;
    padding: 3rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        linear-gradient(-135deg, transparent 30%, rgba(255, 107, 107, 0.05) 50%, transparent 70%),
        radial-gradient(circle at 80% 20%, rgba(0, 212, 255, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 20% 80%, rgba(255, 107, 107, 0.05) 0%, transparent 50%);
    animation: backgroundShift 20s ease-in-out infinite;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    z-index: 10;
}

.footer-logo {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-logo span {
    color: var(--accent);
}

.footer-nav {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.footer-nav a {
    color: white;
    text-decoration: none;
    transition: color 0.3s;
    font-size: 1rem;
    padding: 0.5rem;
    font-weight: 500;
}

.footer-nav a:hover, .footer-nav a:focus {
    color: var(--accent);
}

.copyright {
    margin-top: 1rem;
    opacity: 0.8;
    font-size: 0.875rem;
}

/* Accessibility improvements */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary);
    color: white;
    padding: 8px;
    z-index: 100;
    text-decoration: none;
    display: none;
}

.skip-link:focus {
    display: block;
    top: 0;
}

/* Go to top button */
.go-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.8) 0%, rgba(255, 107, 107, 0.8) 100%);
    color: white;
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    z-index: 99;
    border: 2px solid transparent;
    font-size: 1.25rem;
}

.go-top.show {
    opacity: 1;
    visibility: visible;
}

.go-top:hover, .go-top:focus {
    transform: translateY(-3px);
    border-color: rgba(0, 212, 255, 0.6);
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.8) 0%, rgba(0, 212, 255, 0.8) 100%);
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }
    
    .logo-container {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        gap: 0;
    }
    
    .header-nav {
        margin-left: auto;
    }
    
    .header-nav .nav-links {
        margin-top: 0;
    }
    
    .header-nav .nav-links a {
        font-size: 0.875rem;
        padding: 0.75rem 1.5rem;
        letter-spacing: 0.5px;
    }
    
    .logo {
        margin-bottom: 0;
        font-size: 2.75rem;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero p {
        font-size: 1.125rem;
        max-width: 80%;
        margin: 0 auto;
    }
    
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }
    
    .logo {
        font-size: 2.5rem;
    }
    
    .hero h1 {
        font-size: 2.75rem;
    }
    
    .hero p {
        max-width: 70%;
    }
    
    .grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
    
    .hero h1 {
        font-size: 3rem;
    }
}